An unmanned transport apparatus automatically travels by adjusting brakes, an accelerator, and a steering device in accordance with external environment conditions which have been recognized by a sensor. For example, the unmanned transport apparatus of the prior art is divided into two types; one is using a high frequency transceiver, the other is employing a monitoring camera.
The unmanned transport apparatus using the high frequency transceiver recognizes route conditions according to a loop in which a plurality of high frequency transceivers are installed at regular intervals on the both sides of a road and a high frequency transceiver equipped in a vehicle, which transmits a high frequency signal with the high frequency transceivers of the loop. Also, the unmanned transport apparatus receives high frequency signals from the transceivers of vehicles in front of and behind the vehicle and thus adjusts its speed by a central processing unit of the vehicle for thereby performing unmanned operation.
The unmanned transport apparatus using the monitoring camera detects vehicles ahead using cameras disposed at both sides of the vehicle, calculates a distance to the vehicles ahead using a central processing unit based on triangulation, and controls a speed by calculating a relative velocity with the vehicle ahead by time slots using a vehicle speed sensor.
However, these unmanned transport apparatuses according to the prior art have problems as follows. The unmanned transport apparatus using the high frequency transceiver costs a great deal in establishing and maintaining incidental facilities and sensors on a road. The unmanned transport apparatus using the high frequency transceiver also frequently generates errors in distance detection. The unmanned transport apparatus using the monitoring camera also has several problems of a relatively low velocity, generation of distance error due to difficulty in properly calculating a curve of a road, and lack of function of checking the route to the destination and detecting a current location.